Environmental Friendly Fabrication of Graphene Oxide Immobilized in Chitosan Coupled with Carboxymethyl Cellulose for Removal of Zinc(II) Ions and Oxytetracycline from Aqueous Solution

The fabrication of sustainable materials for decontaminating traditional and emerging contaminants from wastewater is always in need. Graphene oxide immobilized in chitosan and carboxymethyl cellulose (Chit-GO/CMC) hydrogel thin film was developed using an eco-friendly citric acid crosslinker. The morphological images of hydrogel films were recorded by scanning electron microscopy. X-ray diffraction technique was used for crystal structure analysis of the films. The chemical elements were documented by X-ray photoelectron spectroscopy, and the functional groups of thin film was characterized by Fourier Transform Infrared Spectrophotometer. The synthesized pure, binary, and ternary thin films were applied to scavenge bivalent zinc ions and oxytetracycline molecules from aquatic solutions. The higher adsorption capacity was achieved by ternary hydrogel film than pure and binary thin films due to the multifunctional synergetic effect of ternary composite film. The optimum adsorption of Zn(II) and OTC was recorded within 300 min at pH 5 and 9, respectively. The scavenging of Zn(II) and OTC was controlled by chemisorption. The Redlich-Peterson isotherm model was closely fitted for scavenging zinc ions, while the oxytetracycline adsorption was best fitted to the Freundlich model. The modified thin film has been reused for six adsorption-desorption cycles. The hydrogel films could be considered a promising adsorbent for the adsorptive extraction of organic antibiotics and inorganic metal ions from aquatic contaminated environments.